Safety device for vehicle doors



Feb. 13, 1934.

C. E. ELLI$,. JR

SAFETY DEVICE FOR VEHICLE DOORS Filed May 31. 1929 2 Sheets-Sheet lINVENTORY 'ATTORNEYS Feb. 13, 1934. Q ELLIS, JR 1,947,079

SAFETY DEVICE FOR VEHICLE DOORS Filed May 31, 1929 2 Sheets-Sheet 2ATTORNEYS Patented Feb. 13, 1934 UNITED STATES PATENT OFFICE SAFETYDEVICE FOR VEHICLE nooas of Illinois Application May 31, 1929. SerialNo. 367,581

3 Claims.

This invention relates to safety devices for doors, and has particularreference to apparatus for protecting persons against injury in and/orby the doors of vehicles such as elevators, trains, and the like.

The great desirability of a power actuated mechanism for opening andclosing doors has been recognized for many years past and in recentyears such door operating mechanisms have come into use to aconsiderable extent. Their use, however, has been attended withinnumerable accidents, some of them quite serious, because when the dooris actuated to move it to theclosed position while some one is in thedoorway, that person is liable to injury and frequently is severelyinjured by the door, especially as the mechanism for moving the doorwith the required speed and precision must have'considerable power.

It has been proposed to make such a door operating mechanism subject toautomatic control by making the door in two or more parts, one of whichwill be moved relative to the other by engagement with an object in thedoorway, the relative movement of these two parts serving to open orclose an electric circuit whereby the movement of the door is checked orthe door is retracted. Such a mechanism is by no means satisfactory andis objectionable because the automatic control of the door is secured bycontact of the door with the body of a person in the doorway. o

The present invention is directed to the provision of an improved formof control mechanism for controlling the operation of a door in adoorway when moved by a suitable power device, and involves theprovision of a control mechanism which is effective to control theoperation of the door irrespective of any physical contact of any partof the door mechanism with the body of a person in the doorway.

This is accomplished by the provision of means whereby the door will notbe moved to the closed position or will be checked if its movement has Ibeen initiated if any part of a persons body is in the doorway or anypart of his clothing, or if the doorway is partially obstructed in anyother way, as for instance, by a package carried by a person entering ordeparting through the doorway. If the door is in its fully retractedposition and the appropriate mechanism is manipulated to cause it tomove to the closed position at a time when the doorway is obstructed,the controlling mechanism will operate automatically to prevent movement0! the door, this being schematically in Figs. 1 and 2, Fig. 4 beinganradically different from the operation occurring with the mechanismabove referred to wherein the door must move and, engage the person inthe doorway before the controlling mechanism can function at all. If,when movement of the door to the closed position has started, and whilethe door is so moving, some part of ones body or apparel gets into thedoor opening, the automatic mechanism will function to check theoperation of the door irrespective of whether or not there is anycontact of the door with the obstructing object. Under all conditions,the control of the operation of the door is entirely independent ofcontact of the door with an object in the doorway.

These objects are attained in an apparatus which is the best now knownto me by employing a beam of light across the door opening and alight-responsive element such as a photoelectric cell for controllingthe operation of the door mechanism in such a way that the door may moveto its closed position if nothing solid is interposed in the path of thebeam of light, but if the beam is obstructed by the body of a person orby the wearing apparel of a person or by any other object, the movementof the door will be checked irrespective of any contact of the door withthe obstructing object.

For a better understanding of the invention, reference is made to theaccompanying drawings, in which Figure 1 is an electrical circuitdiagram of semiautomatic apparatus for opening and closing the door ordoors of a vehicle such as an elevator, the closing of the door or doorsbeing automatically reversed when the photoelectric cell is disturbed byinterception of thelight ray impinging thereon;

Fig. 2 is an electrical circuit of similar semiautomatic door openingand closing apparatus, the closing of the door being stoppedautomatically when the photoelectric cell is disturbed by intercepticnof the light ray impinging thereon;

Fig. 3 illustrates an electrical controller for operating an electricalelevator or other vehicle, the circuit connections of this controllerbeing controlled by the photoelectric cell arranged as shown in Figs. 1and 2;

Figs. 4 and 5 are views showing a preferred arrangement of thephotoelectric cell and light ray producing apparatus as applied to anelevator having semiautomatic car and shaft door opening and closingapparatus such as is illustrated III interior view of the elevator shaftas seen along the line 4-4 of Fig. 5;

Fig. 6 illustrates a preferred arrangement of photoelectricallycontrolled mechanism for preventing the closure of a manually operatedelevator door when the light ray, directed as illustrated in Fig. 5across the doorway upon the photoelectric cell, is interrupted; and

Fig. '7 illustrates a manner of applying the apparatus of this inventionto the doorway of a railway vehicle or the like.

In these drawings, referring particularly to Figs. 4 and 5, numeral 10designates an elevator car adapted to be driven upwardly and downwardlyin the shaft 11, and adapted to stop at the several fioors to receiveand discharge passengers in the usual way. Access to and from theelevator car 10 is had through the shaft doors 12 located at the severalfioors, these shaft doors being preferably operated by an electric motor13 through the agency of the screw 14, nut 15, and toggle levers 16connected to the door 12, which is illustrated as a double door adaptedto open and close at the center of the elevator car and shaft doorways.The elevator car door 1'7 may also be operated in a similar way by anelectric motor, not illustrated in Figs. 4 and 5, but showndiagrammatically at 18 in Figs. 1 and 2.

Mounted upon the elevator car 10 is a source of light 20, such as anelectric incandescent lamp fitted with a reflector and converging lensas shown in Figs. 1 and 2, which directs a ray of light 21 across theshaft doorway so that this ray 21 is intercepted by the shaft door 12when the door is fully closed as shown in Fig. 4. It is preferred thatthe ray 21 pass outside of the car door 17 and partly inside of theshaft door 12, as shown in Fig. 5, where it is most readily interceptedby any person attempting to go into or out of the elevator after themovement to close the doors has been initiated, whereby greater safetyfor the passengers is assured.

The light issuing from light source 20 falls upon and illuminates thethresholds of the car and shaft doorways, and thus serves the doublepurpose of lighting a passenger's Way into and out of the car andprotecting him against injury in a manner to be described.

Obviously, the light ray 21 may be similarly directed only across thecar doorway as shown in Fig. 7, only across the doorway of shaft door12, or across both the car and shaft doorways, so as to be interceptedby both car door 17 and shaft door 21, if desired. An element of the ray21 3 passes through an opening in the shaft door sill 22 which iscovered by a glass or lens 23 located over a reflector 24 placed in achamber 25 below the shaft door sill 22. This reflector defiects the ray21 outwardly through a grating 26, glass, or like protective coveringfor the opening of chamber 25 into the elevator shaft 11, so that theray impinges upon the photoelectric cell 27 mounted upon the elevatorcar 10, which has come to rest at that fioor to receive or dischargepassengers.

Referring now to Fig. 1, it will be seen that the electrical effectsproduced in the photoelectric cell 2'7 by the ray 21 are amplified by asuitable amplifier 28, supplied with current from the direct currentlines 29 and 30. In order that the electrical effects in thephotoelectric cell may be amplified, the direct current is convertedinto fluctuating current by interrupting the ray 21 periodically bymeans of the shutter 31 consisting of a disc having spaced apertures, aplurality of radial arms, or the like, which is driven by a smallelectric motor 32 connected to the direct current line 29-30. The effectof the shutter is to give the light ray a predetermined frequency ofinterruption.

The amplifier 28 is tuned to respond only to the frequency ofinterruption of the ray 21 so that any other sources of light whichmight otherwise affect the photoelectric cell are ineffective to operatethe door controlling mechanism, as they do not pass through theamplifier. This prevents unintended operation of the system by lightrays coming from within the car or from the floor landing.

In order that the photoelectric cell 27 may be better shielded againstunauthorized sources of light or reflection of light, it is housed in ascreen box 9 having a small aperture through which only the ray element21 may pass to fall directly upon the electrode of the cell.

Instead of interrupting the ray 21 to produce fluctuations in thephotoelectric cell circuit, the source 20 may be replaced by a neon orother gas-filled lamp energized from an alternating urrent source toproduce a fluctuating ray 21.

A solenoid 33 is connected to the output of amplifier 28 in such a waythat when the ray 21 is directed upon the photoelectric cell 27, thecurrent set up therein, which is amplified at 28, energizes solenoid 33which normally holds up its armature 34 against the tension of spring35. When the ray 21 is intercepted, solenoid 33 is deenergized and dropsits armature which is pulled downwardly by spring 35 to open normallyopen contacts 36 and close normally closed contacts 37. The normallyclosed contacts 37 are in the circuit connected by wire 38 to positiveline wire 29, which short circuits the door opening contact 39 whensolenoid 33 drops its lower contacts 40 into engagement with contacts37, whereby solenoid 41 is energized to raise its contacts 42 and 43into engagement with contacts 44 and 45, respectively, which causesenergization of the armatures and field windings of theparallel-connected shaft and car door operating motors 13 and 18 to openthese doors.

The normal operation of the door operating mechanism is controlled bymanual lever or handle 46, the condition of the circuit being as shownin Fig. 1. In order to open the doors when the elevator car comes torest at a fioor to receive or discharge passengers, the car operatormoves handle 46 into engagement with contact 39 to connect positive linewire 29 to solenoid 41, which is energized to pull up its contacts 42and 43 into engagement with respective contacts 44 and 45, which causesenerglzation of the field windings and armatures of motors 13 and 18,which ac cordingly open the shaft and car doors to per mit passage ofthe passengers in the usual way. After the passengers have passedthrough the doors, the operator reverses hand lever 46 to engage doorclosing contact 47, which connects positive line wire 29, throughcontacts 36, bridged by the upper contact 48 of armature 34, wire 49 toenergize solenoid 50, and return by wire 51 to negative line wire 30.

The disconnection of handle 46 from door open ing contact 39de-energizes door opening solenoid 41. which drops its armature todisconnect the door opening motors 13 and 18. The energization ofsolenoid 50 causes it to pull up its armature to engage its contacts 52and 53 with respective contacts 54 and 55 to reverse connections to thearmatures and field windings of door opening motors 13 and 18,respectively. This causes the motors to reverse and close thecorresponding car and shaft doors 17 and 12, respectively.

Inasmuch as the shaft door 12 intercepts ray 21, the photoelectric cell27 would operate and drop its armature 34 to close contacts 37, wherebythe door motors would be energized to reopen the doors, but as this isnot desired, the solenoid 33 is energized directly from line 2936 byengagement of switch lever 56 with fixed contact 57 just before thedoors are completely closed. This is preferably accomplished asillustrated in Fig. 4, by connecting switch lever 56 by links 58 to thedoor operating toggle levers 16 in such a way that opening of the door12 disconnects switch lever 56 from contact 57, whereby the solenoid 33is energized by the photoelectric cell circuit. Conversely, closing ofthe door 12 reconnects switch lever 56 with contact 57, whereby thesolenoid 33 is energized directly from line 2930 and the operation ofphotoelectric cell 27 when the bios ing door 12 intercepts ray 21 isineffective.

It will be seen that, after the operator has thrown handle 46 intoengagement with contact 47 to effect closure of the car and shaft doorsin the manner described, if a person attempts to enter or leave the carthrough the closing doors, that person, his arm, leg or any otherportion of his body, clothing or the like, will intercept the ray 21 andde-energize the photoelectric cell 27. This results in de-energizationof solenoid 33, which accordingly drops its armature 34 to break thecircuit through contacts 36 and motors 13 and 18 to stop the closingmovement of the doors. At the same time, contacts 37 are connected byarmature 34 to energize solenoid 41, whereby the motors 13 and 18 areoperatedto re verse and reopen the doors. When the interception of theray 21 has ceased, solenoid 33 is deenergized and pulls armature 34upward to break contact 37 and restore the circuit through contacts 36,whereby the operator may again close the doors by moving his handle 46into engagement with door closing contact 47.

This arrangement prevents injury to passengers by the closing doors, andas the majority of modern elevators are equipped with safety deviceswhich prevent the energization of the car driving motors until the doorsare completely closed, a double safety element is provided by theapparatus of this invention. One example of such a safety device forcontrolling the operation of the car in accordance with the condition ofthe doors is disclosed in Patent No. 1,648,002, issued Novembar 8, 1927,to H. V. McCormick.

In Fig. 2 a modified form of the apparatus of this invention is showndiagrammatically. The de-energization of photoelectric cell 27, causedby interception of the ray 21", causes de-energization of solenoid 33,which drops its armature 34' which is pulled downwardly by spring 59 tobreak the connection between contacts 60. The power input to theamplifier 28' is alternating current, which can be readily amplifiedwithout requiring the shutter 31 shown in Fig. 1 for producingpulsations in the direct current input.

In this arrangement, the manual control lever for operating the cardoors is a pole-changing electric switch 61. When moved into theposition shown, the doors are opened by the motors 13 and 18'. Whenswitch 61 is moved in the opposite direction, the motors are reversed toclose the doors. Contacts 60 are in the door closing circuit, so that ifthe ray 21' is intercepted by a passenger attempting to enter or leavethe ele-' vator car after the movementto close the doors has beeninitiated by manipulation of switch 61, the resultant de-energization ofthe photoelectric cell27 causes solenoid 33' to drop its armature 34 andbreak the circuit to the motors 18 and 18, whereby the closing movementof the doors is arrested.

When the interception of the ray 21 has ceased, solenoid 33' isre-energized to reclose contacts 60 so that the motors 13' and 18' mayoperate to close the door. This takes place automatically if theoperator has left switch 61 in the door closing position.

If the operator has moved switch 61 from the door closing position whenthe door stopped closing because of the operation of the photoelectriccell, he may move it back to the door closing position, or he may reopenthe door by moving the switch 61 to the door opening position shown inFig. 2. It will be noticed that the action of the photoelectric cell 27'does not affect the door opening circuit in any way. The photoelectriccell cut-out or short-circuiting switch 56 operates in the mannerdescribed above in connection with Figs. 1 and 4.

In Fig. 3 is illustrated diagrammatically an arrangement whereby thephotoelectric cell 27" may be employed to prevent the operation of theelevator driving motor when the ray, arranged as shown in Fig. 5, forexample, is intercepted by a person or other object in the car or shaftdoorways. The elevator car carries the usual controller 62, which isprovided with contacts and electrical connections through which themovement of the car by'the driving motor, not necessary to be shown, iscontrolled, such connections including supply wires 63 and 64 in whichis interposed a switch 65 of any suitable construction,

preferably having a spring 66 which holds this switch in normally openposition. The armature 34 of the solenoid 33" of the photoelectric cell2'7" and amplifier 28", is attached to the switch 65, as shown.

In the event that the ray is intercepted in the manner described, thede-energization of the solenoid 33" causes switch 65 to break theelevator control circuit, so that the car cannot move, even though theoperator manipulates controller 62 in an attempt to start the car. Whenthe interception of the ray ceases, solenoid 33" is reenergized andspring 66 restores the circuit. The short-circuiting switch 56" isoperated in the manner described in connection with Figs. 1, 2 and 4.Obviously, a double safety arrangement controlled by the photoelectriccell may be provided by combining the arrangements of Figs. 1 or 2 withthe arrangement of Fig. 3, as by adding switch 66 to the armature 34 inFig. 1 so that the same photoelectric cell controls the closing of thedoor and the operation of the elevator.

' In Fig. 6, the elevator shaft door 12' may be actuated manually bymeans of the usual toggle lever shown in Fig. 4 and illustrated in theaforementioned McCormick patent. As shown in this patent, the rod 67,which moves upwardly with the toggle when the door 12' is opened, anddownwardly when the door 12' is closed, may be projected downwardlythrough the sill of the door for engagement by a pivoted brake shoe 68which is normally held out of engagement by a spring 69 when the carcarrying it is moving. If the ray 21 arranged as shown in Fig. 5, isintercepted in the manner described, the solenoid 33" of thephotoelectric cell 27' is de-energized, allowing spring 69 to pull itsarmature 34" upwardly so as to swing the shoe 68 into engagement withthe rod 67 and prevent its downward movement, whereby the door 12'cannot be closed. When the interception of the ray has stopped, thesolenoid 33" is re-energized and pulls the brake shoe 68 away from rod67 so that door 12' may be closed. As shown in theaforementionedMcCormick patent, the car controller cannot operate the driving motor solong as the door 12' remains open. Also, this arrangement may becombined with the arrangement shown in Fig. 3, if desired, the samephotoelectric cell performing both of the functions described inconnection with these arrangements.

The application of the safety device of this invention to a railwayvehicle door, as shown in Fig. I, may comprehend any of the arrangementsillustrated in Figs. 1, 2, 3 and 6, and one photoelectric circuit maycontrol all of the doors of the train, or one cell associated with eachdoor may control the individual doors, if desired.

It will be seen that this invention provides a very effective andefficient safety device whereby the dangers attending the operation ofhigh speed elevators or other cars are obviated, and this safety factorpermits the elevators and cars to operate at still greater speedswithout fear of injury to any persons by reason of closing doors or carmovements when a person is located in the doorway. While severalpreferred embodiments of the invention have been illustraed anddescribed herein, it is to be understood that the invention is notlimited to these embodiments, but is susceptible of change in form,detail and arrangement within its scope.

At the same time the ray illuminates the threshold of the car or landingdoorway, whereby it performs a twofold function without additional orseparate apparatus.

' I claim:

1. In combination with a vehicle door, a source directing a beam oflight across the doorway, a light sensitive cell in said beam of light,mechanism for moving said door, means connecting said cell and saidmechanism whereby the cell controls the mechanism, and means responsiveto the closing operation of the door near its closed position forrendering said cell ineffective to control said mechanism.

2. In combination, a car having a doorway movable past a cooperatingdoorway, means disposed on the car for projecting a light across saidcooperating doorway, a light-sensitive device disposed on said car,means associated with said cooperating doorway for reflecting said lightto said device, a door in said cooperating doorway, and means forconnecting said device and said door whereby the device controlsoperation of the door when the light is interrupted.

3. In combination, a car having a doorway movable pas; a cooperatingdoorway, means on said car for projecting a light across said doorways,a light-sensitive device disposed on the car, means associated with thecooperating doorway for reflecting said light to said cell, doors forthe doorways, and means for connecting said cell and said doors wherebythe cell controls the operation of the doors when the light isinterrupted.

CHARLES E. ELLIS, Jn.

